Process of steam drawing and annealing polyester yarn



June 24, 1969 z 3,452,132

PROCESS OF STEAM DRAWING AND ANNEALING POLYESTER YARN Filed Nov. :5.1966 Sheet or 2 June 24, 1969 z 3,452,132

PROCESS OF STEAM DRAWING AND ANNEALING POLYESTER YARN Filed Nov. 5, 1966Sheet of 2 \JZQ6. 4 I

yi \jzg United States Patent US. Cl. 264-290 5 Claims ABSTRACT OF THEDISCLOSURE Within an enclosure, an advancing bundle of polyesterfilaments is heated to at least the second order transition temperatureby an asymmetric impingement of steam, thereby initiating drawing.

This application is a continuation-in-part of my copending applicationSer. No. 274,454, filed Apr. 22, 1963, now abandoned. The inventionrelates to production of filamentary structures from synthetic linearcondensation polymers and, more particularly, to a process improvementinvolving the transfer of heat to and the rapid elevation in temperatureof such structures in a draw zone.

In the production of filamentary structures from synthetic linearpolyesters such as polyethylene terephthalate, it is customary to drawthe filaments to several times their as-spun length in order to enhancesuch physical properties as tenacity and elongation. It is known thatsuch yarns can be drawn to advantage if heated where drawing occurs.Accordingly, polyester yarns have been drawn in a heated liquid or vaporbath, over a heated draw roll and over a heated snubbing device such asa hot pin or a hot plate.

In the manufacture of polyester textile yarns, the drawing step isextremely critical in that nonuniform drawing leads to nonuniform dyeingwhich, in turn, leads to commercially unacceptable fabrics. In order tocontrol drawing so that all the filaments in the yarn bundle are drawnsimultaneously, it is known that the yarn length in which drawing occursmust be restricted to a certain area and not wander back and forth.Initiation of drawing and localization of the draw point on a snubbingpin has disadvantages, particularly when bunching of the filamentsoccurs, so that uneven drawing results, i.e., when the filaments are notlying flat, when the filaments cross over or when several layers offilaments are drawn over the pin. These situations are accentuated athigh speeds.

In commercial production, drawn polyester yarns normally have a boil-offshrinkage in the order of -15%. Consumer prefrence, however, dictates areduction to shrinkage levels less than 10%, the reduction normallybeing accomplished by annealing, e.g., by passing drawn yarn in severalwraps over large heated rolls or by exposing the drawn yarn, at constantlength, to a high dryheat temperature for an extended period of time.

The present invention has as its most important objective the provisionof process improvements which facilitate a rapid and uniform transfer ofheat to undrawn polyester filamentary yarn advancing axially at a high seed.

A corollary objective is to provide effective and effi- 3,452,132Patented June 24, 1969 cient processes for drawing polyester filamentaryyarn rapidly and uniformly.

Another object of the present invention is the provision of a procedurein which such yarns can be drawn and simultaneously annealed.

These and other objectives are accomplished in a high speed processwhich involves the advance of a bundle of polyester filaments in asubstantially uninterrupted path of travel through an enclosurepositioned between feed and draw rolls. Within the enclosure, steam isjetted onto the bundle in an asymmetric impingement intersecting thebundles path of travel. The temperature-pressure relationship of theimpinging steam is such as to localize the draw initiation point byopening up the yarn bundle and raising the individual filamentssubstantially instantaneously to at least their second order transitiontemperature.

The basic process and its variations are described more fully in thefollowing specification and examples wherein reference is made to theaccompanying drawings in which:

FIGURE 1 is a schematic illustration of an apparatus arrangement usefulin a continuous spin-draw process;

FIG. 2 is a partial schematic of an apparatus arrangement useful in asplit spin-draw process;

FIGS. 3-5 are longitudinal sections taken through different jet devicesused in various exemplified tests of the apparatus arrangements shownschematically in FIGS. 1 and 2;

FIGS. 6-8 are transverse sections taken on corresponding lines in FIGS.3-5; and

FIG. 9 is a typical graph of the relationship between peak yarntemperature in the enclosure and boil-01f shrinkage of homopolymericpolyester yarns which have been drawn and annealed in accordance withthe present invention.

The coupled spin-draw apparatus of FIG. 1 includes a spinneret 1 fromwhich polyester filaments 2 are spun. After convergence, the filamentbundle passes over a finish roll 3, in several wraps around feed roll 4and its separator roll 5, through a jet enclosure 6, in several wrapsaround draw rolls 7, 8, and thence to a package 9 which is surfacedriven by a roll 10. The yarn can contact finish roll 3 eithertangentially or in a partial wrap.

In the split process of FIG. 2, filamentary yarn is spun, packaged andsubsequently withdrawn from the package 11, through a guide 12, aroundfeed rolls 4', 5' and through a jet enclosure '6' by draw rolls of thetype shown in FIG. 1.

Various tests of the arrangements shown in FIGS. 1 and 2 are describedand compared hereinafter. In each test run, the jet enclosure 6 (or 6)took the form of one of the three devices shown in FIGS. 3-8, each ofwhich has an angularly disposed steam entrance port a, a yarn inlet b, ayarn exit 0 and an interior yarn passage d. With these devices, steamjetting from port a intersects the yarn advancing through passage d inan asymmetric impingement. The area relationship between the steam inletand outlet is such in the devices of FIGS. 4, 5 as to facilitatedevelopment of critical steam flow at the outlet and therefore ofcondensation on the yarn at temperatures in excess of C. within theenclosure.

Where used herein, the phrase asymmetric impingement refers to thejetting of steam onto and in intersecting relationship with the filamentbundle, i.e., from one side of the bundle. The yarn entrance port b mustbe so designed that the yarn is held in the path of the impinging jet,i.e., it must be centered on the steam entrance port a and must be ofequal or narrower width.

By enclosure is meant the passage or space d through which the filamentstravel in a device of the type shown in FIGS. 3-8, i.e., the passagewhich extends from the end of inlet b to exit c. As such, it iscompletely enclosed except for openings a, b, c, and is normally filledwith steam. Its shape is not critical except that the proper arearelationship of the steam entrance port and the jet exit must bemaintained when critical flow is desired.

The term lubricating finish refers to a yarn coating of a suitabletextile treating agent or a combination of agents such as mineral,vegetable, and animal oils, as for example, a light mineral oil, oliveoil and sperm oil, a process oil such as sulfonated and sulfated estersand their salts or a synthetic material such as a silicone oil,diethylene glycol, a mono-, dior triester such as is prepared from a 12-to 18-carbon monocarboxylic acid, e.g., stearic, and a 2- to l6-carb0nmonoor polyhydric alcohol, e.g., sorbitan, glycerol or glycol. Thetreating agent may also be a soap such as an alkanolamine or alkalimetal salt of a fatty acid, a wax, a biocide or an antistat such as acondensate of from 3 to 20 mols of ethylene or other alkylene oxide withone mol of a compound with an active H atom, e.g., a fatty acid or fattyalcohol containing from 4 to-20 carbon atoms or a salt of an alkyl oroxyalkylene phosphate. The textile treating agents are preferablycombined with an organic liquid diluent, such as a hydrocarbon, ahalogenated hydrocarbon, an alcohol, an ester or a ketone or an ether,preferably with a high-boiling liquid such as kerosene. If desired,these agents may be emulsified in water in accordance with principlesknown to the art. The lubricating finish will usually have aconcentration of about 5-30% solids so as to deposit from about 0.05 to2.5% solids on the yarn.

By polyesters is meant fiber-forming linear condensation polymerscontaining in the polymer chain the carbonyloxy linking radicalsPolymers containing oxy-carbonyloxy radicals are comprehended withinthis group. In the absence of an indication to the contrary, a referenceto polyesters is meant to encompass copolyesters, terpolyesters and thelike. The polyesters may, if desired, contain additives, e.g.,delustrants, viscosity boosters and the like.

Examples of crystallizable, linear condensation polyesters arepolyethylene terephthalate, polyethylene terephthalate/isophthalate (85/15), polyethylene terephthalate/ 5-(sodium sulfo)isophthalate (97/3),poly(p-hexahydroxylene terephthalate), poly(diphenylolpropaneisophthalate), poly(diphenylolpropane carbonate), the polyethylenenaphthalene dicarboxylates (especially those derived from the 2,6- and2,7-isomers) and poly(m-phenylene isophthalate) Filaments spun fromthese polymers may have round or nonround cross seition, e.g., Y,cruciform and the like. The filaments may be composed of one componentor of two polyesters differing from each other in one or more ways so asto form a bicomponent filament.

By essentially simultaneously is meant the period of time a given pointin the yarn length is in the jet enclosure which, at the speedscontemplated herein, ranges from 0.25l0 milliseconds. Where reference ismade to a substantially instantaneous elevation to the second ordertransition temperature, it is indicative of the lesser period of timeduring which the yarn is exposed directly to the impinging steam jet. Asdisclosed in US. Patent 2,556,295 to Pace, crystalline polyethyleneterephthalate has a second order transition temperature (Tg) of about 80C. The amorphous undrawn polyester has a Tg of about 67 C.

Where reported, boil-off shrinkage is determined on a skein of testyarn, the length of which is measured before and after a 60-minuteboil-off treatment to permit calculation of the percent change inlength.

Previous efforts to draw polyester yarns at high speeds without the useof a snubbing device have yielded filaments with undrawn lengths ofrelatively large cross section. Heating the yarns by a jet of steamwithout an enclosure also has provided this undesirable result. Whensuch filaments are dyed, the undrawn lengths dye to a darker shade thando the drawn portions, because of the ease of absorption of a greateramount of dye. Physical properties such as tensile strength will alsovary in an unevenly drawn filament. As a further consequence,intermediate lengths will be overdrawn, often resulting in brokenfilaments and sub-marginal mechanical quality. In the practice of thisinvention, the snubbing device is omitted but undrawn segments areavoided by asymmetrically impinging a jet of steam at near sonicvelocity on the yarn bundle in the draw zone. It is believed that thehigh velocity steam opens the bundle and allows uniform heat transfer tothe individual filaments. By impinging the high velocity steam onto theyarn bundle asymmetrically, the bundle is opened and the rapid andsurprisingly uniform transfer of heat to the filaments permitslocalization of the draw initiation point and consequent uniformdrawing. According to this invention, it is a requisite that the yarn beheated substantially instantaneously, in the draw zone, to a temperatureof at least the second order transition temperature, so that the drawinitiation point will not wander and, thus, cause nonuniform drawing. Inthis connection, satisfactory drawing performance has been achieved injet enclosures as short as one inch. From this, it has been concludedthat passage through the enclosed asymmetrically impinging steam jet issufiicient exposure for drawing and that the period of time involved inthis substantially instantaneous elevation of the yarn to at least thesecond order transition temperature is less than a millisecond. In orderto achieve this necessary, rapid and uniform elevation in temperature,it is desirable to utilize the heat transfer capabilities of condensingsteam.

Steam temperature depends upon yarn denier, steam pressure, yarn speedand the draw ratio. In general, at a given draw ratio, an increase inyarn speed requires an increase in steam temperature. At draw ratiosgreater than 5.0 and at speeds in excess of 2500 y.p.m., steamtemperatures of 200300 C. have been found to give satisfactory resultsand temperatures up to 450 C. have been used with no adverse effects. Atdraw ratios ranging approximately from 3 to 5 and at drawing speeds inexcess of 2500 y.p.m., steam temperatures of to 250 C. have beenadequate to achieve uniform drawing performance.

The maximum operable temperature is related to the fibers sticktemperature. When this temperature is reached, it is believed thatindividual filaments break and stick to the body of the jet device,thereby causing a breakdown in the thread line. Steam temperatures abovethe polymer melting point may be used provided that they do not heat theyarn to the polymer stick point.

In drawing polyester yarns, according to the principles of theinvention, steam pressure must be sufiiciently high to insure fluidvelocities of at least 500 feet/sec. at the point of impingement butsteam pressure, as such, is not critical. Supply pressure will normallyrange from 30-150 p.s.i.g. As noted previously, uniform drawing ofpolyester filaments is obtained by jetting such high velocity steam ontothe yarn asymmetricaly. The impinging steam opens up the yarn bunde andpermits the individual filaments to be rapidly and uniformly heated.Although sonic impingement velocities of 1500-2000 feet per second arepreferred, a velocity of 500 feet per second has been used successfullywith asymmetric impingement at drawing speeds as high as 2750 y.p.m.Although the high velocity steam deflects the yarn from its path andbrings it into grazing contact with the interior lip of the yarnentrance port b, this presents no problem since the draw initiationpoint is located downstream from the entrance port.

Drawing yarns at high draw ratios to obtain maximum tenacity requireslocation of the jet within six inches of the feed roll. This requirementis also preferred for moderate draw ratios, i.e., even in situationsWhere maximum tenacity is not required. When the jet-to-feed-rolldistance becomes too great, the yarn can draw at the feed roll ratherthan in the jet and yarn uniformity is lost. This is believed to becaused by the high draw forces imposing a tension on the filaments highenough to overcome their yield stress and cause the polymer to undergocreep or coldflow. When the time period during which this force isapplied is sufficient to permit the initiation of drawing before thesteam impingement point, the yarn can begin to draw prior to the jet andthe draw initiation point will then recede to the feed roll.

Since an increase in temperature lowers the yield stress, impingement ofthe steam onto the yarn is preferably carried out in a manner to preventany appreciable escape of steam at the yarn entrance port of the jet.This is best achieved by impinging the steam in the direction the yarnis traveling and impingement angles of 2565 give satisfactory results.

Synthetic linear polyester yarns drawn according to the process of thisinvention are found to be remarkably free from dyeing nonuniformitiesand, in particular, those short-length dyeing nonuniformities which havehindered full development of polyester yarns. Furthermore, the processof this invention may be operated at windup speeds of 3200 y.p.m. andhigher without loss of uniform dyeing properties. The outstandingadvantages resulting from this invention are the attainment of uniformheat transfer at high speeds and this in a small amount of equipmentspace.

The residual shrinkage of polyester yarn is primarily dependent on thehighest temperature that the yarn has reached. With homop-olymers, ithas been found necessary to raise yarn temperature above 115 C. in orderto obtain a boil-off shrinkage less than (FIG. 9). Previously, such anannealing effect has been accomplished on advancing yarn by relativelylong periods of exposure to roll surfaces heated to moderatetemperatures of 120-250 C. or by exposure to high temperature gases ofabout 450 C. In this invention, filament temperature can be raised toabove 115 C. in the jet enclosure by utilizing the rapid heat transfercapabilities of condensing steam. In addition to a substantiallyinstantaneous yarn temperature elevation for drawing purposes,condensation of steam on the yarn after its passage through theimpinging jet but within the enclosure has the further effect of raisingyarn temperature sufficiently to provide annealed yarn in which theattained shrinkage is less sensitive to the water content of the yarnfrom, for example, an aqueous finish. In order to obtain condensation atuseful temperatures, the steam in contact with the yarn, i.e., inpassage d, should be above atmospheric pressure.

In this invention, yarn is kept in contact with steam at elevatedpressures in the jet enclosure by designing the jet so that criticalflow occurs at the yarn entrance and exit, e.g., as in FIG. 4. Criticalflow has been defined as a natural phenomenon which occurs when acompressible fluid attains sonic velocity at the exit of a pressurizedsystem. Turbulence associated with sonic velocity undoubtedlycontributes to the over-all efliciency of the system by stripping offthe air layer that surrounds the incoming filaments.

The peak temperature that the yarn reaches will depend upon steamtemperature and pressure in the jet, yarn speed and the length of thejet enclosure. For the annealing effect, the yarn speed and the lengthof the jet enclosure must be such that the yarn is exposed to condensingsteam at elevated pressures for a length of time suflicient to allow theyarn to reach the temperature of the condensing steam and tocrystallize. In the process of this invention, this occurs in theinordinately short time of less than 10 milliseconds. Since the heattransfer during condensation is much more effective in raising yarntemperature than is convection, superheating the steam, e.g., steam at50 p.s.i.g. by as much as 2550 C., has little effect on yarn temperatureand, hence, on shrinkage values obtained in condensation jets. That is,the maximum temperature that the yarn reaches is that of thecondensation temperature corresponding to the steam pressure in the jet.As a consequence, boil-off shrinkage values resulting from the use of ajet exhibiting critical flow, e.g., the type shown in FIG. 4, are afunction of the steam saturation temperature and not the temperature ofthe superheated supply steam. It is nevertheless desirable to usesuperheated steam to prevent flooding of the jet, although excessivesuperheat is to be avoided since in extreme cases the yarn can be heatedabove the saturation temperature of the steam by convection andeffective control of maximum threadline temperature will be lost.

In achieving shrinkage levels of less than 10%, steam pressure is a moreimportant measurement than is steam temperature for selecting annealingconditions. Test runs have shown that steam pressures corresponding tocondensation temperatures of -185 C. result in satisfactory annealing atyarn speeds in excess of 2500 y.p.m.

EXAMPLE I Apparatus for drawing yarn is set up as shown in FIG. 2.Polyethylene terephthalate polymer having a relative viscosity of about25 and containing 0.3% titanium dioxide as a delustrant is melt spuninto a yarn having 34 filaments and wound to a package 11. The yarn 2',protected by a lubricant, is fed by feed roll 4' to enclosure 6' at aspeed of 833 y.p.m., drawn to a denier of about 70 at 2,750 y.p.m. andwound to a package of the type shown at 9 in FIG. 1. In each run, thetreating fluid is jetted onto the yarn bundle at a velocity greater than500 feet per second. The drawing conditions and properties of the drawnyarns are reported in the table. Runs 1, 2 and 4-8 show polyesterfilaments being drawn in their passage through diiferent jet deviceembodiments within each of which the yarn intersects an asymmetric steamimpingement; observed drawing uniformity indicates the tabulated steamsupply temperatures are sufliciently high to raise the filaments to orbeyond their second order transition temperatures. Runs 1 and 4-8, inwhich the yarn has a boil-off shrinkage of 10% or less arerepresentative of an optimum process in which the annealing effect isachieved. In run 3, air is used as the treating fluid and the pooruniformity of the drawn yarn reflects the superiority of steam versusair as a treating fluid.

Yarn from each run was Woven into a taffeta fabric which was scoured /2hour at 70 C., heat set 8 seconds at C. and then dyed with CelanthreneBrilliant Blue FPS (CI61505) for 1 hour at 100 C. Inspection of the dyedfabric revealed the presence or absence of short length dyeingnonuniformities. In the table, the symbol U refers to a highly uniformfabric while the symbol N refers to a nonuniform fabric, i.e., to afabric showing a multiplicity of sections in which the filaments haveabsorbed a greater amount of dye than in neighboring sections.

A comparison of runs 1 and 5 shows that raising the steam temperaturehas little effect on yarn shrinkage when condensation jets are used; theslightly higher boiloff shrinkage in run 5 is attributable to a higherwinding tension. A comparison of runs 1, 6 and 7 shows the effect ofincreased steam pressure (higher saturation temperature) on yarnshrinkage.

In run 8, steam pressure in the jet body at the steam entrance port a(FIG. 5) is 41 p.s.i.g. and the saturationcondensation temperaturecorresponding to this pressure is 142 C. From the graph of FIG. 9, itcan be seen TABLE Jet Yarn properties Dimensions (in.) Treating fluidBoil-off Steam Temp. Pres. Ten. Elong. shrinkage Run Type Length Yarnpassage Yarn exit port (dia.) Type C.) (p.s.i.g.) (g./d.) (percent)(percent) 5 0. 10 X 0. 078 0. 046 X 0.050 0. 053 Steam. 153 50 4. 5 29.8.2 0.10 X 0. 078 0.10 X 0. 078 d 155 50 4. 3 27. 5 11.3 7 0.080 x 0.003 0. 080 X 0. 063 163 50 3. 8 15. 5 11. 3 7 0.080 x O. 063 0. 030 X 0.063 161 50 4. 6 26. 5 0. 4 5 0. 10 x 0.078 0. 046 X 0. 050 188 50 4. 430. 0 8. 4 5 0.10 X 0. 078 0. 046 X 0. 050 186 3'0 4. 2 29. 5 10. 0 5 0.10 x 0. 078 0. 046 X 0.050 232 120 4. G 25. 2 4. 3 5 0. 080 X 0. 063 0.080 X 0. 063 153 50 4. 6 28.0 0. 7

that one would expect a boil-off shrinkage of 6.8% in yarn heated tothis temperature. Comparison of this value with the measured yarnshrinkage of 6.7% shows that boil-off shrinkage is related to the steamsaturation-condensation temperature.

EXAMPLE II Apparatus for drawing yarn is set up as shown in FIG. 1.Polyethylene terephthalate polymer having a relative viscosity of about27 is melt-spun into a yarn having 50 filaments, converged and advancedover lubricating roll 3 and feed roll 4 to a steam jet three inches inlength. The jet has a steam port with a diameter of 0.125 inch, a cavitydiameter of 0.188 inch and a cavity length of 2.75 inches. Except for acircular passage d, its design is generally similar to that shown inFIG. 3. superheated steam at a temperature of 300 C. and a manifoldpressure of 50 p.s.i.g. is impinged asymmertically on the yarn at anangle of 30. The yarn is drawn at a speed of 2890 y.p.m., at a drawratio of 5.7 8, to a final denier of 220. The drawn yarn has a tenacityof 7.4 g./d., an elongation of 11.3%, a boil-off shrinkage of 8.0% and ahigh degree of uniformity. Such a low boil-off shrinkage is indicativeof the annealing efiect.

EXAMPLE III Apparatus for spin-drawing yarn in a continuous process isset up as shown in FIG. 1. A copolyester prepared from ethylene glycoland a 98/2 mixture of the dimethyl esters of terephthalic/S-(sodiumsulfo)-isophthalic acid is melt spun into a -filarnent yarn. The yarn 2is fed by roll 4 to jet 6 at a speed of 976 yards per minute, passedover draw rolls 7, 8 heated to 160 C., drawn to a denier of about 77 at2750 yards per minute and packaged. The jet is the same as that shown inFIG. 3 except for provision of a stringup slot. It is connected to asteam supply having a temperature of 180 C. and a pressure of p.s.i.g.The yarn is drawn in its passage through the jet enclosure, annealed inits passage over heated rolls 7, 8, and packaged. It has a tenacity of2.8 grams per denier, an elongation of 15.5%, a boil-off shrinkage of5.2% and a high degree of uniformity. Such a low boil-off shrinkage isindicative of the annealing efiect.

EXAMPLE IV Apparatus for spinning and drawing yarn in a continuousprocess is set up as shown in FIG. 1. A copolyester prepared fromethylene glycol and a 98/ 2 mixture of the dimethyl esters ofterephthalic/5(sodium sulfo) isophthalic acid, 'having a relativeviscosity of about 19.5 and containing 0.45% titanium dioxide as adelustrant is melt spun into a 34-filament yarn. The yarn 2 containing awater base finish applied by roll 3 (angle of wrap, 951) is fed by roll4 to jet 6 at a speed of 1100 yards per minute, drawn to a denier ofabout at 300 yards per minute, passed over draw rolls 7, 8 heated to C.,and packaged. The jet has an impingement angle of 30 and is similar tothat shown in FIG. 3 except for provision of *a stringup slot. It issupplied with steam having a temperature of 175 C. and a pressure of 30p.s.i.g. The yarn is drawn in its passage through the jet enclosure,annealed in its passage over heated rolls 7, 8 and then packaged. It hasa tenacity of 2.8 grams per denier, an elongation of 29.0%,

a boil-off shrinkage of 8.0%, and a high degree of uniformity.

EXAMPLE V Apparatus for spin-drawings yarn in a continuous process isset up as shown in FIG. 1. Polyethylene terephthalate polymer having arelative viscosity of about 25 and containing 2.0% titanium dioxide as adelustrant is melt spun into a 34 filament yarn. The yarn 2, containinga water-base finish applied by roll 3 (angle of wrap, 951), is fed byroll 4 to jet 6 at a speed of 880 yards per minute, drawn to a denier ofabout 70 to 3046 yards per minute, passed over draw rolls 7, 8 heated to126 C., and packaged. The jet has an impingement angle of 30 and issimilar to that shown in FIG. 3 except for provision of a stringup slot.The jet is supplied with steam having a temperature of 200 C. and apressure of 50 p.s.i.g. The yarn is drawn in its passage through the jetenclosure, annealed in its passage over heated rolls 7, 8 and thenpackaged. It has a tenacity of 4.3 grams er denier, an elongation of29.0%, a boil-ofi shrinkage of 8.2% and a high degree of uniformity.

EXAMPLE VI Apparatus for spinning and drawing yarn in a continuousprocess is set up as shown schematically in FIG. 1. Polyethyleneterephthalate having a relative viscosity of about 50 and containing0.10% titanium dioxide is melt spun into a yarn of 192 filaments. Theyarn 2 is protected by an oil-base finish in the amount of 0.10% solidsby weight. The finish consists of 77 parts of refined kerosene and 33parts of di-(2-ethylhexyl) ester of polyethylene glycol of molecularweight about 200 (an antistatic lubricant). From finish roll 3, yarn 2is fed by roll 4 to jet 6 at a speed of 513 yards per minute, drawn to adenier of 1260 at 2745 yards per minute, treated again with the aboveester to provide 1.1% solids by Weight of treated yarn, passed over drawrolls 7, 8 heated to C. and packaged. The jet has an impingement angleof 30 and is similar to that shown in FIG. 3 except a stringup slot isprovided. The steam port is 'a slot having a width of 0.2 inch and alength of 0.625 inch, with slot Width being parallel to the direction ofyarn travel. The jet is supplied with steam having a temperature of 380C. and a pressure of 50 p.s.i.g. The yarn is drawn and annealed in itspassage through the jet enclosure, further annealed in its passage overheated rolls 7, 8 and then packaged. It has a tenacity of 9.2 grams perdenier, an elongation of 15.0%, a 160 C. dry heat shrinkage of 9.4%, aboilotr" shrinkage of but 3.8% and a high degree of uniformity.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In the high speed production of filamentary yarn, the steps of:advancing a bundle of polyester filaments in a substantiallyuninterrupted path of travel through an enclosure positioned betweenspaced feed and draw rolls; and jetting steam on said bundle, withinsaid enclosure, in an asymmetric impingement intersecting said path oftravel, the velocity of jetting steam being sufficiently high to openthe bundle, the temperature-pressure relationship of the impinging steambeing such as to raise the individual filaments substantiallyinstantaneously to at least their second order transition temperatureand to thereby initiate drawing.

2. The process of claim 1 wherein superheated steam is jetted on thebundle and the time-pressure relationship in said enclosure is such asto lower the steam to its saturation temperature and raise saidfilaments essentially simultaneously to a temperature above 115 C.

3. The process of claim 1 wherein superheated steam is jetted on thebundle, the enclosure has a restricted outlet and the time-pressurerelationship in said enclosure is such as to lower the steam to itssaturation temperature and raise said filaments essentiallysimultaneously to a temperature above 115 C.

4. The process of claim 3 wherein said filaments are melt upon andadvanced continuously to said feed rolls.

5. The process of claim 1 wherein said raw rolls are heated to atemperature of at least about 120 C.

10 References Cited UNITED STATES PATENTS 2,360,352 10/1944 Lodge264-210 2,5 84,043 1/ 1952 Oberly. 2,664,009 12/ 195 3 Emerson.2,622,961 12/ 1952 Finlayson. 3,048,467 8/ 1962 Roberts et a1.

FOREIGN PATENTS 758,398 10/ 1956 Great Britain.

DONALD J. ARNOLD, Primary Examiner.

US. Cl. X.R. 264-210 mg UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3, 52,132 Dated June 2 4-, 1969 Inventor (5)Gilbert PitZl It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

At line 55 in column 1, "prefrence" should be preference At line 67 incolumn 7, "300" should be 3000 In column 9, at line 15 (line 2 of claim4), "upon" should be spun ---5 and at line 16 (line 1 of claim 5), "raw"should be --draw--.

SIGNED AND SEALED Altar:

a man-mm x. suHuYLER. m.

. Omissions? or latants nn Office: a V

